Taking selenium supplements could boost your cholesterol levels and increase your risk of heart disease, English researchers suggest.

Selenium-a trace essential mineral with antioxidant properties—is found in meat, vegetables and seafood. Some people also take selenium supplements because they believe the mineral will reduce the risk for cancer and other diseases.

Study Findings

University of Warwick researchers examined the link between levels of selenium in the blood and fats in the blood in 1,042 people, ages 19 to 64. The study found that participants with blood levels of selenium higher than 1.20 micromoles per liter (pmol/L) had an 8% higher average total cholesterol level and 10% higher non-HDL cholesterol levels (LDL "bad" cholesterol and other cholesterol levels that help predict risk for heart attack), compared with those with the lowest selenium blood levels. Of the participants with the highest selenium levels, 48.2% said they took dietary supplements.

The study was published in The Journal of Nutrition.


Although high selenium levels were not exclusively caused by taking dietary supplements, the findings are cause for concern because the use of selenium dietary supplements is increasing, said study leader Saverio Stranges, MD, PhD.

"This use has spread despite the lack of definitive evidence on selenium supplements efficacy for cancer and other chronic disease prevention. The cholesterol increases we identified may have important implications for public health. In fact, such a difference could translate into a large number of premature deaths from coronary heart disease," Dr. Stranges said.


"We believe that the widespread use of selenium supplements, or of any other strategy that artificially increases selenium above the level required, is unwarranted at the present time," said Dr. Stranges. "Further research is needed to examine the full range of health effects of increased selenium, whether beneficial or detrimental."

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